The present invention relates to an electronic gaming machine and in a particular an electronic gaming machine having a base game and a feature game. The invention has been developed primarily for use as an electronic gaming machine and will be described hereinafter by reference to this application.
The following discussion of the prior art is intended to present the invention in an appropriate technical context and allow its advantages to be properly appreciated. Unless clearly indicated to the contrary, however, reference to any prior art in this specification should not be construed as an express or implied admission that such art is widely known or forms part of common general knowledge in the field.
Conventional gaming machines typically involve awarding prizes to a player according to predetermined combinations of game symbols that appear on an array of game squares displayed on a screen, typically organised into three rows and five columns (a 5×3 array). Other arrays, such as a 3×3 or 4×3, may be used. Each gaming machine randomly selects the game symbols that appear on the array, each column of the array being a “reel”.
In an electronic gaming machine, the mechanical reels are replaced with video images of the reels, which are displayed on a video display screen. The electronic gaming machine has an internal electronic game controller, typically a computer, computational processor or other central processing unit, that controls the display of images on the video display screen so that the reels are visibly spun on the screen to simulate a physical reel of a traditional gaming machine. Electronic gaming machines are also more versatile in presenting game information, varying the probabilities for a player to win a prize and varying the type of game that is played.
One type of electronic gaming machine offers multiple sets of reels to permit a player to play several reels at the same time, depending on the amount that is wagered or bet by the player. For example, a gaming machine could offer four reel sets each having 50 pay lines available for selection by the player. By wagering a suitable amount, such as 200 credits, the player can play all 50 pay lines and thus all four reel sets.
Bonus or “feature” games may also be provided by an electronic gaming machine in addition to a base or main game. Typically feature games use the same set of reels as the main game and are limited to a set of free games operated under a single set of rules. This means that the feature game is restricted by the same set of rules, and so there is no variation in the play of the feature game. Consequently, it is difficult to retain player interest because there is no apparent incentive for the player to continue playing the same electronic gaming machine once the player becomes familiar with the feature game and the main game. Also, it is difficult to retain player interest since there is little differentiation between gaming machines in terms of the main and feature games that are played.
It is an object of the present invention to overcome or substantially ameliorate one or more of the disadvantages of prior art, or at least to provide a useful alternative.
It is an object of the invention in at least one preferred form to provide an electronic gaming machine and a gaming method for an electronic gaming machine that encourages player interest.